I came into this conversation late, but I would like to add a comment. I use Switch Grips in all of my balls. I drill in a shop and our customers are primarily 60/40 Turbo over Vice IT. You must be careful when installing either. If you get a pitch wrong or anything else, you can screw it up. I have a couple of different size inside slugs, because my thumb swells some in the summer and during long tournaments. The beauty is that if I have to fiddle with the thumb by adding or removing tape, I only have to do it once. When I switch balls, I do not have to worry about adjusting tape. The new tabs in the Turbo Switch Grips are very strong and I have not had any issues with any of them breaking. My only real problem with the Vice IT, is that the top ring has a tendency to come unglued. Two balls is enough to use the interchangeable thumbs, if you change balls during a set. I have seen no more cracking with switch Grips than I have with slugs.